In an effort to gain the support of the huge Chinese market, the DVD Forum is studying the possibility of a Chinese-only format based on the HD DVD spec. The move was approved by the Forum's 31st Steering Committee
held in South Korea, September 14.
The Optical Memory National Engineering Research Center, a Chinese
research organization, made a proposal to the Forum's blue laser working group in July to define a China-only format based on HD DVD.
The new format is supposed to have the same disc structure as the HD DVD, using two bonded 0.6-mm-thick platters. But it will slightly modify the physical layer and will simplify the video application layer. The resulting China-only format would be incompatible with a HD DVD player, at least without modifications on both the circuitry and the optical pickup unit (OPU).
Chinese consumer electronics manufacturers had initially proposed another format used for storing HD content, called EVD (Enhanced Versatile Disk). The EVD would be closer to the DVD5 and DVD9 concept since it
would be created by using MPEG-2-based technology and a standard optical red laser (same wavelength as current DVDs). Thus, the EVD players would be compatible with DVD, VCD, SVCD and CD. However, the newly proposed HD-DVD format will be based on another codec, called AVS (Advanced Audio Video Coding Standard). The AVC has been developed by the Chinese AVS workgroup. The workgroup started the effort in June 2002 and is currently working on AVS 1.0.
The AVS standard is compatible with MPEG-2 at the system level, and it involves Chinese proprietary IP in the audio/video-compression algorithm. Compared with the already proposed H.264, the biggest strength of AVS lies in its easy implementation. In addition, from the encoding perspective, the popular H.264 requires more than twice the computing power of MPEG-2. For the same image quality, AVS is claimed to require about 30% less computing power than H.264.
The computing-power advantage that AVS offers arises from the granularity with which the scheme processes an image. H.264 processes an image using 4?4-pixel macro blocks for all applications, from big-screen high-definition TVs to small-screen mobile terminals such as cellular phones. AVS uses an 8?8-pixel macro block. The larger block does not adversely affect AVS performance in big-screen high-definition applications, but it greatly simplifies the coding algorithm, according to proponents of the technology. In addition, the 8?8 block avoids possible patent conflicts with H.264, the AVS group claims.
Although AVS has not officially become China's national standard, Chinese fabless IC companies are working to develop AVS IP and chips.
At the same time, AVS-standard-setters promise that they will pursue a low-priced strategy in licensing the technology. In the past, without proprietary IP of their own, Chinese DVD-player makers had to pay large royalties to the 3C Alliance. The royalties have been a significant impediment to Chinese consumer-electronics enterprises, and therefore, many expect the Chinese market to embrace the low-license-fee strategy of AVS. The AVS Workgroup has previously said that adoption of AVS by Chinese manufacturers could save them $1 billion in licensing fees over the next 10 years.
In addition to AVS support, the Chinese version of HD-DVD will include support for MPEG2, MPEG4 and
Microsoft's Windows Media Video 9 (WMV9). Chinese electronics manufacturers will be able to
choose which of these formats they want to support. If they choose not to support all of the formats, they
will be able to reduce the cost of producing HD-DVD players by lowering their licensing costs.
It is also possible to see both a ROM version for prerecorded content and an recordable version of the new format.
The steering committee has created an ad hoc panel called the Subcommittee on China that will study the
technical feasibility of the Chinese proposal.
The development of the Chinese HD-DVD format could be finished by the end of next year at the earliest, with the first commercial products likely to hit the Chinese market in 2007, said Lu Da, deputy director of the
Optical Memory National Engineering Research Center at Tsinghua University, in Beijing. China apparently intends to establish the HD format before the Olympic games in Beijing in 2008.